text: /* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil -*- */
  /*
   * Copyright (c) 2004-2017 The University of Tennessee and The University
   *                         of Tennessee Research Foundation.  All rights
   *                         reserved.
   * Copyright (c) 2015      Research Organization for Information Science
   *                         and Technology (RIST). All rights reserved.
   * $COPYRIGHT$
   *
   * Additional copyrights may follow
   *
   * $HEADER$
   */
  
  #include "ompi_config.h"
  
  #include "mpi.h"
  #include "ompi/constants.h"
  #include "ompi/datatype/ompi_datatype.h"
  #include "ompi/communicator/communicator.h"
  #include "ompi/mca/coll/coll.h"
  #include "ompi/mca/coll/base/coll_tags.h"
  #include "ompi/mca/coll/base/coll_base_topo.h"
  #include "ompi/mca/coll/base/coll_base_util.h"
  #include "ompi/mca/pml/pml.h"
  #include "coll_tuned.h"
  
  /* scatter algorithm variables */
  static int coll_tuned_scatter_forced_algorithm = 0;
  static int coll_tuned_scatter_segment_size = 0;
  static int coll_tuned_scatter_tree_fanout;
  static int coll_tuned_scatter_chain_fanout;
  
  /* valid values for coll_tuned_scatter_forced_algorithm */
  static mca_base_var_enum_value_t scatter_algorithms[] = {
      {0, "ignore"},
      {1, "basic_linear"},
      {2, "binomial"},
      {0, NULL}
  };
  
  /* The following are used by dynamic and forced rules */
  
  /* publish details of each algorithm and if its forced/fixed/locked in */
  /* as you add methods/algorithms you must update this and the query/map
     routines */
  
  /* this routine is called by the component only */
  /* this makes sure that the mca parameters are set to their initial values
     and perms */
  /* module does not call this they call the forced_getvalues routine instead */
  
  int
  ompi_coll_tuned_scatter_intra_check_forced_init(coll_tuned_force_algorithm_mca_param_indices_t *mca_param_indices)
  {
      mca_base_var_enum_t *new_enum;
      int cnt;
  
      for( cnt = 0; NULL != scatter_algorithms[cnt].string; cnt++ );
      ompi_coll_tuned_forced_max_algorithms[SCATTER] = cnt;
  
      (void) mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
                                             "scatter_algorithm_count",
                                             "Number of scatter algorithms available",
                                             MCA_BASE_VAR_TYPE_INT, NULL, 0,
                                             MCA_BASE_VAR_FLAG_DEFAULT_ONLY,
                                             OPAL_INFO_LVL_5,
                                             MCA_BASE_VAR_SCOPE_CONSTANT,
                                             &ompi_coll_tuned_forced_max_algorithms[SCATTER]);
  
      /* MPI_T: This variable should eventually be bound to a communicator */
      coll_tuned_scatter_forced_algorithm = 0;
      (void) mca_base_var_enum_create("coll_tuned_scatter_algorithms", scatter_algorithms, &new_enum);
      mca_param_indices->algorithm_param_index =
          mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
                                          "scatter_algorithm",
                                          "Which scatter algorithm is used. Can be locked down to choice of: 0 ignore, 1 basic linear, 2 binomial.",
                                          MCA_BASE_VAR_TYPE_INT, new_enum, 0, MCA_BASE_VAR_FLAG_SETTABLE,
                                          OPAL_INFO_LVL_5,
                                          MCA_BASE_VAR_SCOPE_ALL,
                                          &coll_tuned_scatter_forced_algorithm);
      OBJ_RELEASE(new_enum);
      if (mca_param_indices->algorithm_param_index < 0) {
          return mca_param_indices->algorithm_param_index;
      }
  
      coll_tuned_scatter_segment_size = 0;
      mca_param_indices->segsize_param_index =
          mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
                                          "scatter_algorithm_segmentsize",
                                          "Segment size in bytes used by default for scatter algorithms. Only has meaning if algorithm is forced and supports segmenting. 0 bytes means no segmentation. Currently, available algorithms do not support segmentation.",
                                          MCA_BASE_VAR_TYPE_INT, NULL, 0, MCA_BASE_VAR_FLAG_SETTABLE,
                                          OPAL_INFO_LVL_5,
                                          MCA_BASE_VAR_SCOPE_ALL,
                                          &coll_tuned_scatter_segment_size);
  
      coll_tuned_scatter_tree_fanout = ompi_coll_tuned_init_tree_fanout; /* get system wide default */
      mca_param_indices->tree_fanout_param_index =
          mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
                                          "scatter_algorithm_tree_fanout",
                                          "Fanout for n-tree used for scatter algorithms. Only has meaning if algorithm is forced and supports n-tree topo based operation. Currently, available algorithms do not support n-tree topologies.",
                                          MCA_BASE_VAR_TYPE_INT, NULL, 0, MCA_BASE_VAR_FLAG_SETTABLE,
                                          OPAL_INFO_LVL_5,
                                          MCA_BASE_VAR_SCOPE_ALL,
                                          &coll_tuned_scatter_tree_fanout);
  
      coll_tuned_scatter_chain_fanout = ompi_coll_tuned_init_chain_fanout; /* get system wide default */
      mca_param_indices->chain_fanout_param_index=
        mca_base_component_var_register(&mca_coll_tuned_component.super.collm_version,
                                        "scatter_algorithm_chain_fanout",
                                        "Fanout for chains used for scatter algorithms. Only has meaning if algorithm is forced and supports chain topo based operation. Currently, available algorithms do not support chain topologies.",
                                        MCA_BASE_VAR_TYPE_INT, NULL, 0, MCA_BASE_VAR_FLAG_SETTABLE,
                                        OPAL_INFO_LVL_5,
                                        MCA_BASE_VAR_SCOPE_ALL,
                                        &coll_tuned_scatter_chain_fanout);
  
      return (MPI_SUCCESS);
  }
  
  int
  ompi_coll_tuned_scatter_intra_do_this(const void *sbuf, int scount,
                                        struct ompi_datatype_t *sdtype,
                                        void* rbuf, int rcount,
                                        struct ompi_datatype_t *rdtype,
                                        int root,
                                        struct ompi_communicator_t *comm,
                                        mca_coll_base_module_t *module,
                                        int algorithm, int faninout, int segsize)
  {
      OPAL_OUTPUT((ompi_coll_tuned_stream,
                   "coll:tuned:scatter_intra_do_this selected algorithm %d topo faninout %d segsize %d",
                   algorithm, faninout, segsize));
  
      switch (algorithm) {
      case (0):
          return ompi_coll_tuned_scatter_intra_dec_fixed(sbuf, scount, sdtype,
                                                         rbuf, rcount, rdtype,
                                                         root, comm, module);
      case (1):
          return ompi_coll_base_scatter_intra_basic_linear(sbuf, scount, sdtype,
                                                           rbuf, rcount, rdtype,
                                                           root, comm, module);
      case (2):
          return ompi_coll_base_scatter_intra_binomial(sbuf, scount, sdtype,
                                                       rbuf, rcount, rdtype,
                                                       root, comm, module);
      } /* switch */
      OPAL_OUTPUT((ompi_coll_tuned_stream,
                   "coll:tuned:scatter_intra_do_this attempt to select algorithm %d when only 0-%d is valid?",
                   algorithm, ompi_coll_tuned_forced_max_algorithms[SCATTER]));
      return MPI_ERR_ARG;
  }
  